Electrical plug connecter



Aug. 12 1924.

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w. E. SHORE ELECTRICAL PLUG- CONNECTER Filed April 4,

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Patented Aug. 12, 1924.

UNITED STATES WILLIAM E. SHORE, OF NEW YORK, N. Y.

ELECTRICAL PLUG CONNECTER.

Application filed April 4,

To all who-m it may concern:

Be it known that I, WILLIAM E. SHORE,

a subject of the King of Great Britain, and

resident of the city of New York, State of New York, in the. United States of America, have invented certain new-and useful Improvements in Electrical Plug Connecters, described in the following specification and illustrated in the accompanying drawings, that form part of the same.

The principal objects of the invention are, to facilitate'the attachment and removal of electrical devices to .screw socket connections enabling the connection being placed or removed with ease and rapidity and to eliminate the dangers and losses due to the screwing of plugs into the sockets.

A further object isto dispense with the two piece plug connecter while maintaining the essential feature of a rapid breaking of the electrical connection to avoid arcing.

The principal feature of the invention consists in the novel construction and arrangement-of parts whereby a plurality of thread engaging members'are expanded and locked in the socket or are collapsed to release the plug by a longitudinally slidable member. f

In the drawings, Figure 1 is a perspective view of my improved plug shown ready for insertion into'a socket.

Figure 2 is an end view.

Figure 3 is a longitudinal sectional view through the line 3-3 of Figure 2 showing the plug secured in a socket.

Figure 4 is a longitudinal sectional view similar'to Figure 3 showing the plug collapsed.

Figure 5 is a longitudinal, sectional view through the line 55 of Figure 2.

Figure 6 is a perspective detail of the expansible member and the sleeve for expanding same.

In the form ofthe device herein shown the plug centre 1 which may be of any suitable insulating material is substantially cylindrical and is formed with the longitudinal grooves 2, preferably four in'number and arranged in diametrically opposite pairs though any desirable number may be used.

A sheet metal sleeve 3 slidably encircles the plug centre 1 and is formed with longitudinal grooves 4 in the periphery which form the inwardly projecting ribs 5. These ribs are a loose sliding. fit in the grooves 2 and the upper extremities 6 of the ribs are 1921. Serial No. 458,387.

drawn inwardly presenting beveled surfaces.

The lower end of the sleeve is formed with a laterally projecting flange 7 which is cut away opposite the grooves 4 forming radial slots 8.

A pair of sheet metal discs 9 and 10 are secured to the bottom end of the plug centre 1 by the screws 11 and 12 and each is pro- 'vided with a pair of spring fingers 13 extending substantially at right angles and parallel with the side of the centre 1. These fingers are bent inwardly at 14 substantially midway of their length and the upper. ends 15 are curved transversely and formed with transverse thread corrugations to fit the thread of the standard threaded lamp socket.

The fingers 13 normally spring inward to fit loosely in the longitudinal grooves -2 in the plug centre and when in this position the threaded corrugations 15 have a lesser external diameter than the internal diameter of the thread of the socket shell into which the plug is to be placed, so that the plug will enter freely with a straight insertion.

The inturned extremities 6 of the sleeve grooves 4 are adapted upon the outward movement of the sleeve to enter behind the free threaded ends of the spring fingers 13 and expand them outwardly so that their grooved peripheral surfaces correspond with the peripheral diameters of the threaded socket shell and fit the same tightly, said threaded ends sliding in the grooves 4 of the sleeve whioh thus hold them from lateral displacement. The flanges 7 of the sleeve 3 are secured in a cup-shaped member 16 of insulating material which is formed with longitudinal grooves 17 to receive the base ends .of the fingers 13 as the cut is moved outwardly to expand the free ends of the fingers 13.

The cup member 16 is provided with a centralopening 18 through which the electric wires 19 extend. The discs 9 and 10 are provided with a central hole 20 and the plugcentre 1 is formed with a central opening 21 and an eccentrically arranged hole 22 ex-- tending through to the outerend.

A central electric contact/23 is secured by a screw 24 to the outer end of the plug centre and is preferably formed with a flexible outer portion 25 extending over the screw. One of the electric wires extends through the hole 22 and is secured to the contact 23 and the other wire is connected to a contact 26 connected to the spring fingers 13 by the screw 11.. The outer and central electrical contacts are thus established.

In the use of this device the plug centre is normally extended from the cup 16 as shown in Figures 1, 4 and 5, its outward movement being limited by the base of the fingers 13 engaging the bottom of the sleeve 3. In this position the outer threaded ends of the spring fingers 13 rest within the grooves 2 being fully collapsed.

The plug is inserted into the socket with a straight push and when the central contact engages the centre contact of the socket the movement of the plug is arrested but the cup and sleeve will continue to move inwardly. The beveled surfaces 6 of the sleeve engage the fingers 13 expanding them outwardly to engagethe threaded surface of the socket and they are then looked securely in place by the presence of the sleeve behind. them and the connection holds securely against any pull upon the wire.

The spring contact 23 at the end of the plug is desirable in order to allow the threads of the fingers 13 to seat properly in the shell and to avoid undue pressure being exerted in securing the plug in the socket.

WVhen it is desired to remove the lug it it merely necessary .to pull upon tiie on member 16. This draws the sleeve 3, which has no binding action but slips freely, from behind the fingers 13, but they are not released until the sleeve clears them when of their own sprin quality they withdraw into the longitudina grooves in the plug centre,

thus freeing the plug and it pulls strai ht out ofthe socket. A quick break of the e ectrical contact is thus made simultaneously both centre and outer contacts by the simple action of pulling upon the cup member 16 and the danger of arcing is eliminated.

An electric plug connection as herein described is extremely simple in its construction and as it eliminates the necessity of the use of a separate plug cap while retaining all the advantages thereof, it may be produced at a lesser cost than the articles at present so commonly used. It will be noted that the Wires are not connected to the operis eliminated.

-What I claim as my invention is 1. An electric plug connecter, comprising a central insulating member having longitudinal grooves in the periphery, a plurality of spring fingers normally resting in said grooves and having thread corrugations, and means external to the central insulating member slidable longitudinally in said grooves adapted to engage in sliding con-' tact with said spring fingers to lock said fingers in engagen'ient with the threaded socket.

2. An electric plug connecter, comprising, a central insulating member having longitudinal grooves in the periphery, a plurality of spring fingers normally resting in said grooves and rigidly connected at one endto said central member, a cup member enclrcling said central insulating member having longitudinal grooves in its inner periphery to receive said fingers, and means secured to said cup member and extending into said grooves to spring said fingers outwardly to engage and grip the socket.

3. An electric plug connecter, comprising,

a central insulating member having lcmg1-' tudinal grooves in the periphery, a plurality of spring fingers normally resting in said grooves and rigidly connected at one end to said central member, a sleeve encircling said central member and having longitudinal grooves forming ribs slidably engaging the grooves in the central member, the grooves in said sleeve being adapted to receive and hold the spring fingers from lateral displacement.

4. An electric plug connecter, comprising, a central insulating member, contacts carried thereon adapted to be expanded to engage in locking contact with the socket shell, and a sleeve member movable longitudinally adapted to expand said contacts, said sleeve member being entirely independent of the wire connections to the contacts carried in the central member.

WILLIAM E. SHORE. 

